Mercury time delay switch



June 13, 1967 s. v. WORTH 3,325,607,

MERCURY TIME DELAY SWITCH Filed July 8, 1960 Fig. l

2 Sheets-Sheet 1 Fig.

INVENTOR. SIDNEY V. WORTH BYMKW ATTORNEY 7 June 13, 1967 s. v. WORTH3,325,607

MERCURY TIME DELAY SWITCH Filed July 8, 1960 2 Sheets-Sheet 2 INVENTOR.SIDNEY V. WORTH BY N I ATTORNEY United States Patent Pennsylvania FiledJuly 8, 1960, Ser. No. 41,537 25 Claims. (Cl. 200-33) The presentinvention relates to an electric switch, and more particularly to anelectric mercury switch having a time delay between the actuation of theswitch to one of its positions and the actual opening or closing of theswitch.

For the operation of many types of electrically operated devices, it isoften desirable to have a switch provided with a time delay. The timedelay may be between the actuation of the switch to its on position, andthe actual closing of the switch, but will provide substantially nodelay between the actuation of the switch to its oif position and theopening of the switch. Furthermore, it is often desirable to provide atime delay switch wherein the delay time is between the actuation of theswitch to its off position and the actual opening of the switch, butwill provide substantially no delay time between the actuation of theswitch to its on position and-the actual closing of the switch. Incertain operations it is desirable to have a delay time betweenactuation of the switch to its open and closed position and the actualopening and closing of the switch.

Furthermore, it is also desirable to have a time delay switch in whichthe delay time can be varied. In order to preclude the possibility ofloss of liquids in the switch, it is desirable to seal the switchhousing. Therefore, the means for varying the delay time must beexternal of the switch housing and preferably should not pierce odextend through the wall defining the switch housing.

Heretofore, it has been conventional to use mercury .in time delayswitches. Since mercury has a large amount of surface tension, there wasa limit to the minimum size of the flow passage through which themercury flows as the switch is moved between its off and on positions.Thus, the size of the flow passage for the mercury presented a limit tothe amount of timedela'y which can be obtained with a mercury time delayswitch,

It is an object of the present invention to overcome the above and otherdisadvantages of the prior art.

It is another object of the present invention to provide a novel timedelay switch.

It is another object of the present invention to provide a novel mercurytime delay switch having a delay period between the actuation oftheswitch to its on position and the actual closing of the switch. i

It is another object of the present invention to provide a novel mercurytime delay switch having a delay period between the actuation of theswitch to its off position and the actual opening of the switch.

It is still another object of the present invention to provide a novelmercury time delay switch wherein the time delay capable of beingobtained is not dependent on the size of the flow passage for themercury.

It is still another object of the present invention to provide anelectric switch having a delay period between the actuation of theswitch to its on position and the actual closing of the switch, buthaving substantially no delay time between the actuation of the switchto its off position and the opening of the switch.

It is still another object of the present invention to provide anelectric switch having a delay period between the actuation of theswitch to its off position and the actual opening of the switch, .buthaving substantially no delay time between the actuation of the switchto its on position and the closing of the switch.

.end walls 14 and 16. A partition 18, positioned intermediate the walls14 and 16 and parallel thereto, divides 3,325,607 Patented June 13, 1967It is a further object of the present invention to provide an electricswitch having a time delay which may be varied.

It is a further object of the present invention to provide a novelswitch wherein the time delay can be ex tended by the provision of aliquid above the mercury in said switch, and having means forcontrolling the flow of said liquid.

It is a further object of the present invention to provide a novelmercury timedelay switch wherein the delay time can be controlled by avalve member which does not extend through the housing of said switch,

It is a still further object of the present invention to provide amercury time delay switch which is simple, easy to manufacture andcontains a minimum number of parts.

Other objects will appear hereinafter.

For the purpose of illustrating the invention there is shown in thedrawings forms which are presently preferred; it being understood,however, that this invention is not limited to the precise arrangementsand instrumentalities shown.

FIGURE 1 is a cross-sectional elevational view of one embodiment of thepresent invention.

FIGURE 2 is a cross-sectional view lines 2-2 in FIGURE 1.

FIGURE 3 is a perspective view of the switch shown in FIGURE 1.

. FIGURE 4 is a schematic cross-sectional view of the switch shown inFIGURE 1 in its off position.

FIGURE 5 is a schematic cross-sectional view of the switch in FIGURE 4immediately after said switch has taken along the been turned to its onposition.

FIGURE 6 is a schematic cross-sectional view of the switch in FIGURE 4in its on position.

FIGURE 7 is a schematic cross-sectional view of the switch in FIGURE 4immediately after being rotated to its off position.

FIGURE 8 is a partial cross-sectional view of another embodiment of thepresent invention.

FIGURE 9 is a cross-sectional view of still another embodiment of thepresent invention.

FIGURE 10 is a cross-sectional view lines 10-10-in FIGURE 9.

FIGURE 11 is an exploded view of the embodiment shown in FIGURE 9.

FIGURE 12 is a schematic cross-sectional view of the switch in FIGURE 9in its on position.

FIGURE13 is a schematic cross-sectional view of the switch in FIGURE 9immediately after being rotated to its off position.

FIGURE 14 is a schematic -cross-sectional view of the taken along the iswitch in FIGURE 9 in its off position.

FIGURE 15 is a schematic cross-sectional view of the switch in FIGURE 9immediately after being rotated to its on position.

Referring to the drawings in detail, wherein like numerals indicate likeelements, there is shown in FIGURE 1 a mercury time delay switchdesignated generally as 10.

Switch 10 comprises a cylindrical housing 12 having the housing 12 intotwo substantially identical chambers. The partition '18 is provided witha hole 20 adjacent its bottom edge so that mercury may flow from onechamber through the hole 20 into the other chamber as the switch 10 ismanipulated between its oh and on positions.

The partition 18 is preferably provided with spaced pockets 22 and 24 onone side thereof. As shown in FIG- URES 1 through 7, the pockets 22 and24 are disposed within the partition 18 on opposite sides of the hole20.

However, it will be understood by those skilled in the art that thepockets 22 and 24 may be provided by securing U-shaped channel memberson one side of the partition 18. Shields 26 are provided on oppositesides of the partition 18 adjacent the uppermost surface of thepartition 18. The shields 26 serve a purpose to be describedhereinafter. A partially tapered hole 28 extends through the partition18 within the confines of the shields 26. A valve member having atapered seating portion for cooperation with the tapered portion of hole28 is provided within the housing 12.

As seen more clearly in FIGURES 1 and 4 through 7, end wall 14 isprovided with a flexible portion 32. Flexible portion 32 may be aflexiblediaphragm or bellows. The valve member 30 is fixedly secured tothe inner surface of the flexible portion 32. The periphery of theflexible portion 32 is fixedly secured to the housing 12 and the endwall 14 so as to preclude leakage. A pair of electrodes 34 extendthrough the end wall 16 and have their ends disposed in one of thepockets 22 and 24 as shown more clearly in FIGURES 1 and 2.

A plate 36 is fixedly secured to the lowermost peripheral surface of thehousing 12 and extends outwardly to one side of the housing 12 in anaxial direction. An L- shaped bracket 38 has one arm thereof fixedlysecured to the plate 36 in any conventional manner such as by the screws40. The other arm of the L-shaped bracket 38 is provided with a threadedhole through which extends the threaded member 42. The said other arm ofthe L-shaped bracket 38 is substantially parallel to the end wall 14 andthe threaded member 42 is substantially coaxial with the valve member30.

The flexible portion 32 is preferably concave when the tapered portionon the valve member 30 cooperates with the tapered portion on the hole28 to preclude flow through said hole 28. One end of the threaded member42 abuttingly engages the outer surface of the flexible portion 32 andmaintains the valve member 30 in a closed disposition. The valve member30 is movable to an open position by rotation of the threaded member 42.Since the flexible portion 32 is concave in the closed position of thevalve member 30, the threaded member 42 need not be fixedly secured tothe flexible portion 32 and the resiliency of the flexible portion 32moves the valve member 30 from a closed position to an open postion. Theextent of the open position of the valve member is determined by theposition of the threaded member 42.

The mercury and other liquids are admitted to the interior of thehousing 12 through a hole in said housing. After the mercury and otherliquids have been admitted into the housing 12, the hole is thenpermanently sealed by a sealing cap 44. A plurality of means may be usedto close the hole for admitting mercury and other liquids to the housing12, the sealing cap 44 is shown solely for illustrative purposes. Thus,it will be seen that the switch comprises a sealed housing 12 having avalve member therein capable of being operated from outside of saidhousing 12 without piercing the walls of said housing 12. Thus, thereare no moving parts extending through the wall of the housing 12 whichare subject to leakage. Also, when the switch 10 has been assembled, themovable liquids are permanently sealed therein and yet the switch 10 iscapable of having a variable time delay.

The housing 12 is supported by a U-shaped support 46 havingsubstantially upright arms 48. A boss 50 is fixedly secured to theperiphery of the housing 12 on one side thereof. A pin 52 extends in aradial direction from the boss 50 and is rotatably mounted in one of thearms 48. A boss 54 is fixedly secured to the periphery of housing 12diagonally opposite to the boss 50. A pin 56 extends from the boss 54 ina radial direction and is rotatably supported by the other arm 48. Aknob 58 is fixedly secured to the free end of the pin 56.

As seen more clearly in FIGURES 2 and 3, the knob 58 is provided with apointer 59 which is capable of cooperating with suitable indicia so asto indicate whether the switch 10 is in its off or on position. Forpurposes of illustration, the indicia has not been illustrated inFIGURES 2 and 3 since the indicia would conceal other features of theswitch 10. The pins 52 and 56 are coincident with the partition 18.Since the boss 54 and pin 56 are fixedly secured to the housing 12, thehousing 12 is rotatable about a radial axis by rotation of the knob 58.Rotation of the knob 58 is the means for opening or closing the switch10 as will be made clear hereinafter.

As shown more clearly in FIGURES 4 through 7, the housing 12 ispartially filled with mercury 60. The remainder of the housing 12 issubstantially filled with a liquid, such as oil 62. The interfacebetween the oil 62 and the mercury 60 is shown at 64. Thus, it will beseen that the amount of mercury 60 is substantially less than the amountof oil 62. Any suitable liquid may be used so long as the liquid islighter than the mercury 60. Preferably, the amount of mercury 60 andoil 62 is less than the volume of the housing 12 thereby defining an airspace 66 for permitting expansion and contraction due to temperaturechanges.

In FIGURE 4, the switch 10 is shown in its off position. The mercury 60is disposed to one side of the partition 18 while the oil 62 is disposedon both sides of the partition 18. A small amount of mercury will bepresent within the pockets 22 and 24, however the electrodes 34 arespaced apart so the switch 10 is in an off position.

When the switch 10 is rotated to an on position, the mercury within thecavities 22 and 24 immediately flows to the lower right hand corner ofthe housing 12 thereby closing the switch 10 without a delay as shown inFIG- URE 5. The mercury 60 flows through the hole 20 from the left handside of the partition 18 to the right hand side and occupies a positionas shown in FIGURE 6. The rate of flow of mercury through the hole 20depends on the position of the valve member 30. The mercury 60 cannotflow through the hole 20 at a rate faster than the rate of flow of oil62 through the hole 28. Since the valve member 30 is provided with atapered seat engaging end, and since the hole 28 is provided with atapered seat portion, the rate of flow of oil 62 through the hole 28 canbe accurately controlled so as to provide a time delay greater than tenminutes if desired. 7

If the switch 10 is rotated to an off position as shown in FIGURE 4, therelative position of the oil 62 and mercury 60 is shown in FIGURE 7immediately after the switch 10 has been rotated to its off position. Itwill be noted that the mercury 60 will flow through the hole 20 to thechamber on the left hand side of the partition 18 with the same timedelay.

Thus, it will be seen that the switch 10 has an instant on position anda time delay between the rotating of the switch 10 to its off positionand the opening of the switch 10. By varying the size of the openingbetween the hole 28 and the valve member 30, and by varying the size ofthe hole 20, the time delay could last for more than thirty minutes. Asa practical matter, a number of hours in delay time may be obtained.Since the valve member 30 is fixedly secured to the flxible portion 32,and since the position of the flexible portion can be varied bymanipulation of the threaded member 42, the length of time delay may bevaried to suit any particular purpose.

FIGURE 8 discloses a second embodiment of the present invention,designated generally 10'. The switch 10' is substantially identical withthe switch 10. The size of the opening 20 in the switch 10 controls therate of flow of the mercury in conjunction with the rate of flow of theoil 62. In a switch, such as switch 10, there is a limit to the minimumsize of the opening 20 since the surface tension of mercury preventsflow when the hole approaches a diameter of 0.020 inch. If suflicienthead is put on the mercury, mercury can be forced to flow through asmaller hole. However, there are limits to the size of the head whichcan be produced, and the provision of a mercury head requires more spaceand a larger amount of mercury. The mercury switches of the presentinvention are designed so as to have a length from less than one inch toa length of several inches. Thus, it will be seen that the provision ofa mercury head is impractical in a switch such as switch 10.

The switch comprises a housing 12 having an end wall 16' correspondingto the structure shown in FIG- URES 1 through 7. In place of thepartition 18 in switch 10, switch 10 is provided with a partition 18'.As seen more clearly in FIGURE 8, the housing 12 is provided with a well70 juxtaposed to the partition 18 and having a width greater than thewidth of partition 18'. The partition 18' is provided with a hole 20adjacent its lowermost edge within the well 70.

In the switch 10', suiflcient mercury 60 is provided so that mercury 60is in the well 70 on both sides of the partition 18'. Since there isalways some mercury on both sides of the partition 18, there is nomeniscus at the hole 20', therefore there is no minimum size for thehole 20. Thus, it is possible to increase the time delay in the switch10 'over the time delay in the switch. 10.

The amount of mercury 60 in the switch 10 as shown in FIGURE 8, issubstantially the minim-um amount of mercury needed for the switch 10'.It will be noted that the mercury 60 in FIGURE 8 is divided into twoparts separated by the surface area 72. Since the surface area 72 isrelatively large, there is no meniscus present to interfere with theflow of the mercury.

It will be understood that switch 10' is substantially identical in allother respects with the switch 10.

FIGURES 9 through disclose still another embodiment of the presentinvention designated generally as 76. The switch 76 comprises acylindrical housing 78 having end walls 80 and 82.

The end wall 80 is provided with a radially extending flange 84. Theradially extending flange 84 cooperates with a face plate 86 formounting the switch 76 on a substantially upright wall 90. The faceplate 86 is provided with a central hole therethrough through which thehousing 78 extends. The face plate 86 is provided with a plurality ofholes 88 for suitable mounting elements such as nails or screws forsecuring the face plate 86 to the wall 90.

The housing 78 is divided into two substantially identical chambers byan axially extending partition 92. The partition 92 is provided with ahole 94 adjacent its lowermost surface at one end thereof. Since thehousing 78 rotates about its longitudinal axis which is substantiallyperpendicular'to the wall 90, the partition 92 is coincident with theaxis of rotation.

As seen more clearly in FIGURES 9 and 11, the end wall 82 is providedwtih a flexible portion 96. An inner housing 98 is supported by thepartition 92. The inner housing 98 is substantially coextensive with theflexible portion 96.

The inner housing 98 comprises a bottom wall 100 extending from eitherside of the partition 92 and substantially perpendicular thereto.Upright walls 102 extend from the bottom wall 100 to the housing 78. Arear wall 104 extends upwardly from the bottom wall 100 to the housing78 and is substantially perpendicular to the walls 100 and 102.

As seen more clearly in FIGURES 9 and 10, the partition 92 is providedwith a V-shaped notch 106. A hole 108 is provided in the rear wall 104coextensive with the V-shaped notch 106.

A valve member 110* is positioned within the housing 98 and is providedwith an end 112 fixedly secured to the inner surface of the flexibleportion 96. The other end 114 of the valve member 110 is tapered andcooperates with the V-shaped notch 106 on the partition 92 to controlthe flow of a liquid, such as oil, from one side of the partition '92 tothe other side thereof. A bracket 116 is fixedly secured to a convenientsurface such as wall 82. A threaded member 118 extends through athreaded hole in the bracket 116. One end of the threaded member 118abuts the flexible portion 96 in the region of the end 112 of the valvemember 110. The liquids are admitted to the housing 78 through a hole inthe end wall 80. The hole in the end wall is then closed by any meanssuch as by a sealing cap 120 which is shown solely for illustrativepurposes.

Electrodes 122 extend through the end wall 82 as shown more clearly inFIGURE 11. The electrodes 122 are substantially parallel to one anotherand extend through the end wall 82 in such a manner that said electrodesare on the same side of the partition 92.

The inner housing 98 is provided so as to prevent contact between theoil 62 and the flexible portion 96. Since the flexible portion 96 has aplurality of positions, the switch 76 would be inaccurate if theflexible portion 96 were permited to contact the oil 62. Also, theflexible portion 96 need not be oil-resistant. It will be noted that therear wall 104 is substantially thicker than the other walls in theswitch 76 so that the valve member can extend through the hole 108 so asto preclude the entry of oil into the inner housing 98 and at the sametime cooperate with the V-shaped notch 106 to control the flow of theoil 62.

FIGURES 12 through 15 are schematic end views disclosing the operativepositions of the switch 76. For purposes of illustration, the end wall82 and the flexible portion 96 are not shown in FIGURES 12 through 15.FIGURE 12 shows the switch 76 in its on position. In FIGURE 12, it willbe noted that suflicient mercury 60 is provided so that the electrodes122 are bridged thereby.

FIGURE 13 discloses the switch 76 immediately after the housing 78 hasbeen rotated about its longitudinal axis to an off position. It will benoted that the switch 76 has substantially no delay time between its onand oif position. FIGURE 14 discloses the switch 76 in its off positiona short interval of time later after the mercury has reached same levelin both chambers. It will be noted that the mercury 60 is present in asuflicient quantity so that the mercury is on both sides of thepartition 92. Thus, the hole 94 has no minimum dimension since there isno meniscus at the hole 94.

FIGURE 15 discloses the switch 76 immediately after being manipulatedfrom an 011 position to an on position. It will be noted that asubstantial delay is provided between the time the switch 76 ismanipulated to its on position and the moment that the electrodes 122are bridged by the mercury 60. Thus, the switch 76 is an instant offswitch and delay on switch.

The flow of the mercury 60 is dependent on the rate of flow of the oil62 due to the size of the flow passage between the tapered end 114 onthe valve member 110 and the V-shaped notch 106 in the partition 92. Theswitch 76 is provided with an air space 66 above the oil 62 in the samemanner as set forth above.

While each of the switches 10, 10 and 76 have been provided with avalved hole in a central partition, it will be appreciated that a holemay be provided in the partition which is not valved. In this case, thetime delay would not be variable. While each of the switches 10, 10" and76 have been disclosed as having oil above the mercury, it will beappreciated that any liquid lighter than mercury may be substitutedtherefor.- Furthermore, it will be obvious to those skilled in the artthat the valve member and the aperture or hole in the partition may beeliminated, thereby relying solely on the control of the flow of mercuryfor the time delay.

In each of the switches 10, 10' and 76, the oil and the mercury arepermanently sealed within the housing of the switches. The valve memberon each of said switches is contained wholely within the housing,therefore the external wall of the housing is not pierced therebyproviding a possibility for leakage. In each of the above switches, theelectrodes are on the same side of the partition and the housings arerotatable about an axis coincident with the partition which divides thehousings into substantially identical chambers. In each of the aboveswitches, the time delay is capable of being varied at will. In switchesand 76, the size of the hole in the partition has no minimum limit.

The housing 98 may be filled'with oil 62 if desired. An oil-resistantflexible portion 96 would be required. Also, the valve member 110 wouldnot require a rubbingfit 'with the hole 108. Since the valving action ofthe oil takes place at the V-shaped notch 106, the presence of oilwithin housing 98 will not interfere with the metering of the oil.

The shields 26 permit the housing 12 to tilt to a greater degree.Therefore, the switch 10 may have a greater time delay since a largeramount of mercury may be provided without having the mercury flowingthrough hole 28.

The electrodes-need not be positioned near the internal periphery of thehousing 12. The time delay of switch 76 can be increased by raising thelevel of the electrodes. In addition, the electrodes 34 may extendthrough either end wall of the housing 12. Alternatively, one of theelectrodes could extend through the end wall 16 while the otherelectrode extends through the wall of housing 12. In this case, only theelectrode extending through the wall 16 would extend to the pockets inthe partition. Alternatively, one of the electrodes in switch 10' couldextend through the wall of the well 70 in which mercury is alwayspresent. Since the mercury in the pocket 24 is spaced from the mercuryin the well 70, there is no possibility of the switch 10' being on inall positions of the housing 12'.

If the pockets 22 and 24 in the switch 10 were eliminated, the switch 10would have a delay period when manipulated to either the on or offposition.

While the means for varying the position of the flexible portion in theswitches 10, 10 and 76 has been shown as a threaded member extendingthrough a bracket, it will be appreciated that other mechanical meansmay be substituted therefor. For example, a cam or a pivoted lever maybe substituted for the threaded members on the switches 10, 10 and 76.Since all of the elements of the switches 10, 10' and 76 are containedwithin the housing of said switches except for the threaded members, theswitches are simple, easy to manufacture and have a long life.

The present invention may be embodied in other specific forms withoutdeparting from the spirit or essential attributes thereof and,accordingly, reference should be made to the appended claims, ratherthan to the foregoing specification as indicating the scope of theinvention.

I claim:

1. A mercury time delay switch comprising a sealed housing, a partitiondividing said housing into two substantially identical chambers, a holein said partition adjacent a bottom edge of said partition, mercurypartially filling said housing, means for rotatably mounting saidhousing for causing said mercury to flow through said hole from onechamber to another, and a pair of electrodes in one of said chambers onthe same side of said partition, said electrodes being spaced apart soas to be bridged by said mercury when said mercury is in said onechamber, said partition having a second hole which is located in a planehigher than the plane of said first-men-' tioned hole, a fluid lighterthan mercury substantially filling the remainder of said chambers, and aselectively operable valve means for controlling the flow of the fluidthrough said second hole in said partition thereby controlling the timedelay of the bridging of said electrodes by said mercury.

2. A mercury time delay switch in accordance with claim 1 including ashield on said partition, said shield being disposed between said holesin said partition.

3. A mercury time delay switch in accordance with claim 1 wherein saidvalve means includes a valve member disposed within one of said chambersand selectively movable toward and away from said second hole to controlflow of said liquid through said second hole.

4. A mercury time delay switch in accordance with claim 1 including aflexible portion on a wall of said housing, said valve means including avalve member extending between said flexible portion and said partition,and mechanical means outside of said housing for selectively moving saidflexible portion thereby moving said valve member relative to saidpartition.

5. A mercury time delay switch in accordance with claim 4 wherein saidhousing is cylindrical and said flexible portion is a portion of an endwall of said housing.

.6. A mercury time delay switch comprising a sealed housing, a partitiondividing said housing into two substantially identical chambers, saidpartition having a hole therethrough adjacent the bottom edge thereof,mercury partially filling said housing, means for rotatably mountingsaid housing for causing said mercury to flow through said hole from onechamber to another, a pair of electrodes in one of said chambers on thesame side of said partition, said electrodes being spaced apart so as tobe bridged by said mercury when said mercury is in said one chamber,spaced pockets on one side of said partition, each one of saidelectrodes having an end thereof positioned in one of said pockets saidpockets being of sufficient size so as to retain an amount of mercurycapable of bridging said electrodes immediately after movement of saidhousing to an on position.

7. A mercury time delay switch comprising a sealed housing, a partitiondividing said housing into two substantially identical chambers, saidpartition having a hole therethrough adjacent the bottom edge thereof,mercury partially filling said housing, means for rotatably mountingsaid housing for causing said mercury to flow through said hole from onechamber to another, a pair of electrodes in one of said chambers on thesame side of said partition, said electrodes being space-d apart so asto be bridged by said mercury when said mercury is in said one chamber,a well in said housing, said hole extending through a portion of saidpartition positioned in said well, the mercury in said housing beingalso positioned in said well, and the level of the mercury in said wellbeing above said hole in all positions of said housing.

8. A mercury time delay switch comprising a sealed housing, a partitiondividing said housing into two substantially identical chambers, a holein said partition adjacent the bottom edge of said partition, mercurypartially filling said housing, means for rotatably mounting saidhousing for causing said mercury to flow through said one hole from saidone chamber to another, a pair of electrodes in one of said chambers onthe same side of said partition, said electrodes being spaced apart soas to be bridged by said mercury when said mercury is in said onechamber, said partition having a second hole which is located in a planehigher than the plane of said first-mentioned hole, a fluid lighter thanmercury substantially filling the remainder of said chambers, aselectively operable valve means for controlling the flow of fluidthrough said second hole in said partition thereby controlling the timedelay of the bridging of said electrodes by said mercury, a flexibleportion on a wall of said housing, said valve means including a valvemember extending between said flexible portion and said partition,mechanical means outside of said housing for selectively moving saidflexible portion thereby moving said valve member relative to saidpartition, said housing being cylindrical in shape, said flexibleportion being a portion of an end wall of said housing, a well in saidhousing, said hole extending through a portion of said partitiondisposed within said well, the mercury in said housing being alsodisposed within said well, and the level of the mercury in said wellbeing above said hole on both sides of said partition in all positionsof said housing.

9. A mercury time delay switch comprising a sealed housing, a partitiondividing said housing into two substantially identical chambers, a holein said partition adjacent a bottom edge of said partition, mercurypartially filling said housing, means for rotatably mounting saidhousing for causing said mercury to flow though said hole from onechamber to another, a pair of electrodes in one of said chambers on thesame side of said partition, said electrodes being spaced apart so as tobe :bridged by said mercury when said mercury is in said one chamber,said means for rototably mounting said housing enabling said housing torotate about an axis coincident with said partition, said axis being thelongitudinal axis of said housing, and a valve member extending to aV-shaped notch in said partition, said valve member cooperating withsaid notch to control the flow of a liquid lighter than said mercurydisposed within said housing in said chamhers.

10. A mercury time delay switch in accordance with claim 9 including awall within said housing substantially perpendicular to said parition,said valve member extending through a hole in said wall, said wall beingpositioned between said notch and an end wall of said housing.

v11. A mercury time delay switch in accordance with claim 10 wherein aportion of said end wall is flexible, said valve member being fixed toan inside surface of said flexible portion, and a mechanical meansoutside of said housing for selectively moving said flexible portionthereby causing relative movement between said valve member and saidnotch.

12. A mercury time delay switch in accordance with claim 11 including aface plate for rotatably mounting said housing, said face platecooperating with a flange on the other end wall of said housing formounting said housing to an upright wall.

13. A mercury time delay switch comprising a sealed housing, a partitiondividing said housing into two substantially identical chambers, a holein said partition adjacent a bottom edge of said partition, mercurypartially filling said housing, means for rotatably mounting saidhousing for causing said mercury to flow through said hole from onechamber to another, a pair of electrodes in one of said chambers on thesame side of said partition, spaced pockets in said housing on said oneside of said partition, each of said electrodes having an end thereofpositioned in one of said pockets, at well in said housing, said holeextending through a portion of said partition disposed within said well,said mercury being in said well above said hole on both sides of saidpartition in all positions of said housing.

14. A mercury time delay switch comprising a sealed housing, a partitiondividing said housing into two chambers, a hole in said partitionadjacent a bottom edge of said partition, mercury partially filling saidhousing, means mounting said housing for rotation about an axiscoincident with said partition for causing said mercury to flow throughsaid hole from one chamber to another, a pair of electrodes in one ofsaid chambers on the same side of said partition, and spaced pockets insaid one chamber, each one of said electrodes having an end thereofpositioned in one of said pockets.

15. A mercury time delay switch comprising a sealed housing, a partitiondividing said housing into two chambers, a hole in said partitionadjacent a bottom edge of said partition, mercury partially filling saidhousing, means mounting said housing for rotation about an axiscoincident with said partition for causing said mercury to flow throughsaid hole from one chamber to another, a pair of electrodes in one ofsaid chambers on the same side of said partition, spaced pockets in saidone chamber, each one of said electrodes having an end thereofpositioned in one of said pockets, a well in said housing, said holeextending through a portion of said partition disposed within said well,the mercury in said housing extending into said well and being abovesaid hole on both sides of said partition in all positions of saidhousing.

16. In a mercury delay time switch having a housing divided into twochambers, and mercury partially filling said housing for flow through ahole in said partition from one chamber to another, the improvementcomprising a well on said housing, said hole extending through a portionof said partition disposed within said well, the mercury in said housingbeing also disposed within said well, and the level of the mercury insaid well being above said hole on both sides of said partition in allpositions of said housing.

-17. In a mercury time delay switch having a housing divided by apartition into two chambers, mercury partially filling said housing, ahole in said partition for permitting the mercury to flow from onechamber to another, a pair of electrodes in one chamber only, theimprovement comprising pockets in said one chamber, each of saidelectrodes having an end thereof positioned in one of said pockets,whereby a time delay is provided when said housing is moved to an offposition only.

18. A mercury time delay switch having a housing divided into twochambers by a partition, a hole in said partition adjacent a bottom edgethereof, mercury partially filling said housing for flowing through saidhole from one chamber to another, the improvement comprising thepartition being in a plane substantially perpendicular to thelongitudinal axis of said housing, a second hole in said partition in aplane higher than the plane of said first hole, a valve member :forcooperation with said second hole, said valve member being fixedlysecured to the inner surface of a flexible portion of an end wall ofsaid housing, a pair of electrodes on one side of said partition, and afluid substantially filling said housing and being lighter than mercury.

19. A mercury time delay switch in accordance with claim 3 wherein thelongitudinal axis of said valve member is substantially coincident withthe plane of said partition.

20. A mercury time delay switch comprising a housing divided by apartition into two chambers, mercury partially filling said housing, ahole in said partition for permitting the mercury to flow from onechamber to another, a second hole in said partition for permitting thefluid in said housing above said mercury to flow from one chamber toanother, a pair of electrodes in one chamher only, means for moving saidhousing between an otf position and an on position, said mercury beingin said one chamber in the on position of said housing, and means insaid one chamber for retaining a portion of said mercury therein whensaid housing is in the oif position, said means retaining said portionof said mercury so that such electrodes are not bridged by said portionof said mercury, and said portion of said mercury being suflicient tobridge said electrodes when said housing is in its on position.

21. A time delay switch comprising a housing, a partition for dividingthe housing into two sections, an electrically conducting fluid withinone of said sections, a second nonconducting fluid lighter than saidelectrically conducting fluid filling the rest of said housing, saidp-artition having holes therethrough, said housing being rotatable, -apair of electrical connectors within one of said sections, saidelectrically conducting fluid having suflicient volume to bridge saidconnectors in one position of said housing, the flow of said secondfluid through said partition holes controlling the flow of saidelectrically conducting fluid.

22. A time delay electrical switch comprising: a pivotable capsulehaving two compartments separated by a wall, said compartments having aconductive liquid therein; an unrestricted conductive liquid passage inthe normally lower end of said wall and an adjust-able metering passagein the normally upper end of said wall whereby the flow of conductiveliquid bet-ween compartments is controlled by said metering passage inthe passage of fluid between compartments; and electrodes in at leastone compartment adaptable to be bridged by said conductive 1 1 liquid,said electrodes being connected through said capsule.

23. A time delay electrical switch comprising: a pivotable capsulehaving two fluid compartments therein separated by a wall; a pair ofelectrodes in at least one of said compartments, each electrodeextending through the capsule to the exterior; an electricallyconductive liquid in said compartment; an unrestricted communicatingpassage near the bottom of said Wall between said compartments to permitfree flow of said conductive liquid therebetween; and an adjustablemetering passage connecting said fluid compartments at the top of saidwall for metering fluid tending to be displaced by said conductiveliquid whereby flow of said conductive liquid between compartments iscontrolled by said fluid through said metering passage.

24. A time delay switch as set forth in claim 23 wherein saidelectrically conductive liquid is mercury.

25. A time delay flow control of mercury comprising: a hermeticallysealed vessel containing a charge of mercury; a partition separatingsaid vessel into two compartments, said vessel being rockable with saidpartition nutatable about a vertical plane; a passage through saidpartition at the lower end thereof of a size no larger than to permitthe free flow of said mercury therethrough, and an adjustable meteringpassage at the top end of said 12 partition to change thecross-sectional area of said metering passage to meter the fluid betweensaid compartments tending to be displaced by said flow of mercurybetween said compartments upon said vessel being rocked whereby mercuryflow is delayed in accordance with the metering of fluidbetweentcompartrnents.

References Cited UNITED STATES PATENTS 1,374,571 4/1921 Hummel 2514-3352,644,866 7/1953 Turnupseed et a1. 200-33 2,831,077 4/1958 Salyer 200332,851,547 9/1958 Hartz 20033 3,003,044 10/1961 Davis et a1. 200-33FOREIGN PATENTS 100,179 1/ 1937 Australia.

ROBERT K. SCHAEFER, Primary Examiner.

R. M. WOOD, M. LEVY, E. J. SAX, B. A. GILHEANY,

Examiners.

ROBERT S. MACON, S. B. SMITH, Assistant Examiners.

1. A MERCURY TIME DELAY SWITCH COMPRISING A SEALED HOUSING, A PARTITIONDIVIDING SAID HOUSING INTO TWO SUBSTANTIALLY IDENTICAL CHAMBERS, A HOLEIN SAID PARTITION ADJACENT A BOTTOM EDGE OF SAID PARTITION, MERCURYPARTIALLY FILLING SAID HOUSING, MEANS FOR ROTATABLY MOUNTING SAIDHOUSING FOR CAUSING SAID MERCURY TO FLOW THROUGH SAID HOLE FROM ONECHAMBER TO ANOTHER, AND A PAIR OF ELECTRODES IN ONE OF SAID CHAMBERS ONTHE SAME SIDE OF SAID PARTITION, SAID ELECTRODES BEING SPACED APART SOAS TO BE BRIDGED BY SAID MERCURY WHEN SAID MERCURY IS IN SAID ONECHAMBER, SAID PARTITION HAVING A SECOND HOLE WHICH IS